Shackle devices are employed in automatic poultry processing machines in which poultry carcasses are guided individually through processing stations. For this purpose, each poultry carcass is suspended by the ankles in the shackle, so that the poultry carcasses are held suspended with the legs pointing upwards. Rotating shackles find application particularly in the cutting up of the poultry carcass in order to produce pieces appropriate for consumption, such as halves, legs, wings, etc., since processing procedures can be carried out in this way on different levels of the carcass starting from the conveyance motion.
From EP 0 444 782 A1, a shackle device is known in the which the shackle can rotate. The shackle fastened to a conveyor is equipped for this purpose with a cam element at a vertical axis. The cam element gets into connection with a stationary cam element in the course of the conveyance and causes the shackle to rotate 90.degree.. Both the original position and the 90.degree.-rotated position are locked in place by a ball catch.
It is disadvantageous in this device that the rotating motion does not take place without jerks and collisions, which at the desired processing speeds lead to uncontrolled swinging and turning motions that impair the processing. The cause of this is the high initial rotational acceleration of the shackles, as well as the torque necessary to overcome the resistance of the rotary catch.